How can we know that whatever was written by someone in history is actually by him and not by someone else?

Question

I was having a conversation with my friend about a historian who wrote about a certain period in my country, but then my friend said “how do you he isnt lying and how do you it is really written by him?” i still cant find a counter argument to this

In: Other

Answer 1

Some documents have more evidence of their validity than others, but at the end of the day, everything you’ve ever read could be false.